CN103278825B - Method for determining satellite navigation signal quality evaluation parameters - Google Patents

Abstract

The invention provides a method for determining satellite navigation signal quality evaluation parameters. The satellite navigation signal quality evaluation parameters comprise Gabor bandwidth, error vector magnitude (EVM), amplitude error, phase error, pseudo-code consistency, phase deviation, phase loss, S curve offset and delay stability. By changing an ideal pseudo-code generating mode, common spread spectrum signals such as binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK) can be evaluated, various special navigation signals such as binary offset carrier (BOC), alternate binary offset carrier (AltBoc), time division alternate binary offset carrier (Td-AltBoc) and time multiplexed binary offset carrier (TMBOC) can be evaluated; and by the high-precision evaluation of pseudo-code phase and carrier phase, each evaluation item of the navigation signals can be highly precisely evaluated, and the requirement on navigation satellite effective load testing can be met.

Description

A kind of defining method of satellite navigation signals quality assessment parameter

Technical field

The present invention relates to a kind of defining method of satellite navigation signals quality assessment parameter, belong to technical field of satellite navigation.

Background technology

In the development process of Navsat useful load, for verifying the correctness of navigation signal, investigating the distortion of signal generative process introducing, need a kind of satellite navigation signals method for evaluating quality; In Navsat in orbit process, be the navigation signal quality that monitor satellite is broadcast, also need a kind of navigation signal method for evaluating quality.

At present, satellite navigation signals quality evaluation can be carried out by the following method:

Method 1, utilizes the method for commonality vector signal analyzer;

Method 2, utilizes the method for hardware or software receiver;

Method 3, utilizes the method that baseband signal gathers.

But carry out navigation signal quality evaluation by above-mentioned 3 kinds of methods, there are the following problems: (1) only to general spread-spectrum signal, as BPSK, QPSK etc. assess, can cannot assess the navigation signal of specific type, as AltBoc, TMBOC etc.(2) Evaluation accuracy is lower, only can meet the needs of the navigation signal that monitor satellite is broadcast, and cannot meet the needs of Navsat useful load test; (3) only can evaluation part index item, the technical indicator such as associated loss, S curve skew cannot be assessed.

Summary of the invention

Technology of the present invention is dealt with problems and is: overcome the deficiencies in the prior art, provide a kind of defining method of satellite navigation signals quality assessment parameter, can assess various types of navigation, Evaluation accuracy can be improved, and there is wider scope of assessment, can assess indexs such as associated loss, S curve skews.

Technical solution of the present invention is:

A defining method for satellite navigation signals quality assessment parameter, described satellite navigation signals quality assessment parameter comprises Gabor bandwidth, error vector magnitude EVM, range error, phase error, pseudo-code consistance, phase deviation, associated loss, S curve skew and delay stability of time;

Concrete steps are as follows:

(1) sample frequency f is set _s, utilize satellite navigation signals generated clock source, generate sampled clock signal and pps pulse per second signal, same source sampling is carried out to described satellite navigation signals, obtain the navigation signal after sampling;

(2) utilize the navigation signal after sampling, carry out the spectra calculation of navigation signal, and calculate Gabor bandwidth;

(3) time delay of each road pseudo-code relative to sampling start time and the carrier phase of each road pseudo-code in the navigation signal after calculating sampling, described pseudo-code is pseudo-code phase relative to the time delay of sampling start time;

(4) carrier phase that step (3) draws is utilized, generate cosine and sinusoidal carrier, peel off the carrier wave in navigation signal, obtain I roadbed band navigation signal and Q roadbed band navigation signal, draw eye pattern and planisphere, calculate the error vector magnitude EVM of navigation signal, range error and phase error;

(5) utilize the pseudo-code phase that step (3) draws, calculate multichannel pseudo-code phase poor, determine pseudo-code consistance;

(6) utilize the carrier phase that step (3) draws, calculate multichannel carrier phase differential, calculate the phase deviation of component of signal;

(7) the base band navigation signal that the pseudo-code phase utilizing step (3) to draw and step (4) obtain, calculates associated loss;

(8) utilize the base band navigation signal that step (4) draws, draw the relevant peaks curve of navigation signal, calculate S curve skew;

(9) data of each collection after arriving to pulse per second (PPS) rising edge all utilize above-mentioned steps (3) to calculate pseudo-code phase, obtain the pseudo-code phase of 24 hours, utilize the pseudo-code phase calculation delay stability of 24 hours.

Carry out same source sampling described in step (1), comprise the following steps:

A () utilizes frequency synthesizer and the described clock source utilizing navigation signal to generate, the frequency described in generation step (1) is f _ssinusoidal signal;

B frequency is f by () _ssinusoidal signal incoming radio frequency signal collecting device, as the clock signal of RF signal collection equipment;

C clock source that () utilizes waveform generator and navigation signal to generate, generates pps pulse per second signal, pulse per second (PPS) to be the cycle be two level signals of 1 second;

(d) by pps pulse per second signal incoming radio frequency signal collecting device, as the trigger pip of collecting device;

E () starts collecting device;

F () arranges drainage pattern:

(i), when pulse per second (PPS) rising edge arrives, start to gather;

(ii) acquisition time is the PN-code capture of the tested navigation signal of twice;

(iii) sample frequency is f _s;

(iv) after sampling terminates, data storage will be collected to obtain, wait for the arrival of pulse per second (PPS) rising edge next time, and start to gather next time;

(v) the whole collection duration is greater than 24 hours.

The carrier phase of each road pseudo-code and pseudo-code phase in calculating navigation signal described in step (3),

Comprise the following steps:

(3.1) iteration step length of pseudo-code phase and carrier phase is set;

(3.2) carry out carrier phase calculating, concrete steps are as follows:

(3.2.1) according to carrier phase iteration step length, cosine carrier and the sinusoidal carrier with different initial phases are set, carry out mixing with measured signal;

(3.2.2) two paths of signals after mixing is by wave digital lowpass filter, and obtain I roadbed band signal and Q roadbed band signal, the bandwidth of low-pass filter is set as 1.5 times of navigation signal bandwidth;

(3.2.3) generate pseudo-random code, and the I roadbed band signal that obtains of step (3.2.2) and Q roadbed band signal carry out related operation respectively, obtain I road related function and Q road related function;

(3.2.4) I road related function step (3.2.3) obtained and Q road related function are added, and offset the cross-correlation part in two-way related function;

(3.2.5) using the sum functions of two-way related function as likelihood function, carry out maximal possibility estimation, draw the maximum likelihood estimator of carrier phase;

(3.3) the pseudo-code phase step calculating each road pseudo-code in navigation signal is as follows:

(A) utilize the cosine carrier phase place that step (3.2) obtains, peel off the carrier wave in navigation signal, obtain base band navigation signal;

(B) according to pseudo-code phase iteration step length, the base band navigation signal obtained is set and is correlated with, obtain related function in the pseudo-code and step (3.2.1) with different initial phases;

(C) related function step (3.2.2) obtained, as likelihood function, carries out maximal possibility estimation, draws the maximum likelihood estimator of pseudo-code phase;

(3.4) judge whether the precision of pseudo-code phase and carrier phase meets the accuracy requirement of navigation signal quality evaluation, if the method for meeting terminates, if do not meet, after the iteration step length of pseudo-code phase and carrier phase is reduced into original 0.1 times, proceed to step (3.2).

Determine that pseudo-code consistance is specially in described step (5): with a road any in multichannel pseudo-code for reference, this road pseudo-code phase and other each road pseudo-code phase are subtracted each other, and the maximal value of difference is as pseudo-code consistance.

Calculate delay stability of time in described step (9) to be specially:

(5.1) utilize step (3) to obtain the pseudo-code phase of 24 hours, phase value number is 86400;

(5.2) by the pseudo-code phase of 24 hours in units of 100 o'clock, order divide into groups, obtain 864 groups;

(5.3) ask the mean value of interior 100 pseudo-codes of each group, obtain 864 mean values;

(5.4) maximal value of these 864 mean values is deducted minimum value, difference is as delay stability of time.

The present invention's advantage is compared with prior art:

(1) by changing the generating mode of desirable pseudo-code, general spread-spectrum signal can not only be assessed, as BPSK, QPSK etc., and the navigation signal of various specific type can be assessed, as BOC, AltBoc, Td-AltBoc and TMBOC etc.

(2) estimated by the high precision of pseudo-code phase and carrier phase, high precision test and appraisal can be carried out to each estimation items of navigation signal, the needs of Navsat useful load test can be met.

(3) can compose pilot signal power, the property indices such as eye pattern, planisphere, EVM, range error, phase error, pseudo-code consistance, component of signal phase deviation, associated loss and S curve skew assesses, index spreadability is wider.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of the inventive method;

Fig. 2 is pseudo-code phase in the present invention and carrier phase estimation method process flow diagram;

Fig. 3 is the method flow diagram generating likelihood function during carrier phase is estimated.

Embodiment

Satellite navigation signals quality assessment parameter comprises Gabor bandwidth, error vector magnitude EVM, range error, phase error, pseudo-code consistance, phase deviation, associated loss, S curve skew and delay stability of time;

As shown in Figure 1, the defining method of satellite navigation signals quality assessment parameter provided by the invention, concrete steps are as follows:

(1) sample frequency f is set _s, utilize satellite navigation signals generated clock source, generate sampled clock signal and pps pulse per second signal, same source sampling is carried out to described satellite navigation signals, obtain the navigation signal after sampling;

Carry out same source sampling described in step (1), comprise the following steps:

A () utilizes frequency synthesizer and the described clock source utilizing navigation signal to generate, the frequency described in generation step (1) is f _ssinusoidal signal;

B frequency is f by () _ssinusoidal signal incoming radio frequency signal collecting device, as the clock signal of RF signal collection equipment;

C clock source that () utilizes waveform generator and navigation signal to generate, generates pps pulse per second signal, pulse per second (PPS) to be the cycle be two level signals of 1 second;

(d) by pps pulse per second signal incoming radio frequency signal collecting device, as the trigger pip of collecting device;

E () starts collecting device;

F () arranges drainage pattern:

(i), when pulse per second (PPS) rising edge arrives, start to gather;

(ii) acquisition time is the PN-code capture of the tested navigation signal of twice;

(iii) sample frequency is f _s;

(iv) after sampling terminates, data storage will be collected to obtain, wait for the arrival of pulse per second (PPS) rising edge next time, and start to gather next time;

(v) the whole collection duration is greater than 24 hours;

(2) utilize the navigation signal after sampling, carry out the spectra calculation of navigation signal, and calculate Gabor bandwidth, the power Spectral Estimation of navigation signal can adopt welch period map method, but is not limited to the method;

(3) time delay of each road pseudo-code relative to sampling start time and the carrier phase of each road pseudo-code in the navigation signal after calculating sampling, described pseudo-code is pseudo-code phase relative to the time delay of sampling start time;

Calculate carrier phase and the pseudo-code phase of each road pseudo-code in navigation signal, as shown in Figure 2, comprise the following steps:

(3.1) iteration step length of pseudo-code phase and carrier phase is set;

(3.2) carry out carrier phase calculating, concrete steps are as follows:

(3.2.1) according to carrier phase iteration step length, cosine carrier and the sinusoidal carrier with different initial phases are set, carry out mixing with measured signal;

(3.2.2) two paths of signals after mixing is by wave digital lowpass filter, and obtain I roadbed band signal and Q roadbed band signal, the bandwidth of low-pass filter is set as 1.5 times of navigation signal bandwidth;

(3.2.3) generate pseudo-random code, and the I roadbed band signal that obtains of step (3.2.2) and Q roadbed band signal carry out related operation respectively, obtain I road related function and Q road related function;

(3.2.4) I road related function step (3.2.3) obtained and Q road related function are added, and offset the cross-correlation part in two-way related function;

(3.2.5) using the sum functions of two-way related function as likelihood function, carry out maximal possibility estimation, draw the maximum likelihood estimator of carrier phase;

Carrier phase correction is the carrier phase measurement deviation that the cross-correlation in order to remove due to code is introduced.Carrier phase correction has two kinds of methods:

(1) formula correction method: adopt following formula to correct carrier phase estimated value

$\mathrm{\Δ\θ}=\arctan \left\{\frac{\mathrm{Cor}(Q,I)}{\mathrm{Cor}(I,I)}\right\}=\arctan \left\{\frac{\mathrm{Cor}(I,Q)}{\mathrm{Cor}(Q,Q)}\right\}$

Wherein, Δ θ is correcting value; Wherein I represents the conjunction road of each component of signal of branch road in the same way, and Q represents the conjunction road of each component of signal of quadrature branch, and Cor () represents related operation.

(2) impact that special carrier tracking loop eliminates cross-correlation is designed, see Fig. 3.

(3.3) the pseudo-code phase step calculating each road pseudo-code in navigation signal is as follows:

(A) utilize the cosine carrier phase place that step (3.2) obtains, peel off the carrier wave in navigation signal, obtain base band navigation signal;

(B) according to pseudo-code phase iteration step length, the base band navigation signal obtained is set and is correlated with, obtain related function in the pseudo-code and step (3.2.1) with different initial phases;

(C) related function step (3.2.2) obtained, as likelihood function, carries out maximal possibility estimation, draws the maximum likelihood estimator of pseudo-code phase;

Phase estimator calibration of the output results is the measured deviation that the cross-correlation in order to remove due to code is introduced.For this reason, when the spreading code that each road signal adopts is selected, can the code phase measuring deviation introduced of the cross-correlation of spreading code of calculated in advance Chu Ge road signal, and form form, when carrying out signal quality testing, correction test result of tabling look-up.

(3.4) judge whether the precision of pseudo-code phase and carrier phase meets the accuracy requirement of navigation signal quality evaluation, if the method for meeting terminates, if do not meet, after the iteration step length of pseudo-code phase and carrier phase is reduced into original 0.1 times, proceed to step (3.2);

(4) carrier phase that step (3) draws is utilized, generate cosine and sinusoidal carrier, peel off the carrier wave in navigation signal, obtain I roadbed band navigation signal and Q roadbed band navigation signal, draw eye pattern and planisphere, calculate the error vector magnitude EVM of navigation signal, range error and phase error;

The error vector magnitude EVM computing method of modulation signal are:

$\mathrm{EVM}=\sqrt{\frac{1}{N}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{|{\stackrel{\→}{S}}_{\mathrm{real}}^n-{\stackrel{\→}{S}}_{\mathrm{ideal}}|}^2}$

The computing method of range error are:

$E_{\mathrm{amp}}=\sqrt{\frac{1}{N}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\left|\right|{\stackrel{\→}{S}}_{\mathrm{real}}^n|-|{\stackrel{\→}{S}}_{\mathrm{ideal}}\left|\right|}^2}$

The computing method of phase error are:

$E_{\mathrm{pha}}=\sqrt{\frac{1}{N}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{|\mathrm{pha}\left({\stackrel{\→}{S}}_{\mathrm{real}}^n\right)-\mathrm{pha}\left({\stackrel{\→}{S}}_{\mathrm{ideal}}\right)|}^2}$

(5) utilize the pseudo-code phase that step (3) draws, calculate multichannel pseudo-code phase poor, determine pseudo-code consistance;

Determine that pseudo-code consistance is specially: with a road any in multichannel pseudo-code for reference, this road pseudo-code phase and other each road pseudo-code phase are subtracted each other, and the maximal value of difference is as pseudo-code consistance;

(6) utilize the carrier phase that step (3) draws, calculate multichannel carrier phase differential, calculate the phase deviation of component of signal; Because the generation of satellite navigation signals adopts digital intermediate frequency modulation technique, the code that same carrier wave is modulated aligns when digital signal generates, and after first carrier wave Shang Ge road, same road pseudo-code merge, then carry out carrier modulation.Now, the phase deviation of gauge signal component, do not need the relation considering code phase, only need the carrier phase deviation weighing I road and Q road signal.Therefore, for digital medium-frequency signal generating mode, the phase deviation of gauge signal component, only need the phase relation considering I road carrier wave and Q road carrier wave.

(7) the base band navigation signal that the pseudo-code phase utilizing step (3) to draw and step (4) obtain, calculates associated loss;

The computing method of one-channel signal or the signal correction loss of conjunction road are:

$\mathrm{CL}\left[\mathrm{dB}\right]=P_{\underset{{\mathrm{Ideal\; S}}_{\mathrm{BB}-\mathrm{PreProc}}}{\mathrm{CCF}}}\left[\mathrm{dB}\right]-P_{\underset{{\mathrm{Real}S}_{\mathrm{BB}-\mathrm{PreProc}}}{\mathrm{CCF}}}\left[\mathrm{dB}\right]$

Wherein,

$\left\{\begin{array}{c}{P}_{\underset{{\mathrm{IdealS}}_{\mathrm{BB}-\mathrm{PreProc}}}{\mathrm{CCF}}}\left[\mathrm{dB}\right]=\max \left(20{\log }_{10}\right|{\mathrm{CCF}}_{{\mathrm{IdealS}}_{\mathrm{BB}-\mathrm{PreProc}}}\left(\mathrm{\ϵ}\right)\left|\right)\\ P_{\underset{{\mathrm{Real}S}_{\mathrm{BB}-\mathrm{PreProc}}}{\mathrm{CCF}}}\left[\mathrm{dB}\right]=\max \left({201\mathrm{og}}_{10}\right|{\mathrm{CCF}}_{{\mathrm{Real}S}_{\mathrm{BB}-\mathrm{PreProc}}}\left(\mathrm{\ϵ}\right)\left|\right)\end{array}\right.$

$\mathrm{CCF}\left(\mathrm{\ϵ}\right)=\frac{\underset{0}{\overset{T_P}{\∫}}{S}_{\mathrm{BB}-\mathrm{PreProc}}\left(t\right)S_{\mathrm{ref}}(t-\mathrm{\ϵ})\mathrm{dt}}{\sqrt{\left(\underset{0}{\overset{T_P}{\∫}}{\left|S_{\mathrm{BB}-\mathrm{PreProc}}\left(t\right)\right|}^2\mathrm{dt}\right)\left(\underset{0}{\overset{T_P}{\∫}}{\left|S_{\mathrm{ref}}\left(t\right)\right|}^2\mathrm{dt}\right)}}$

S _bB-PreProct () is the baseband signal after down-converted, S _reft () is reference signal, T _pfor integration period, length equals the integral multiple in yard cycle.

A () is for one-channel signal:

● S _reft () is ideal baseband signal;

● S _{ideal-PreProc}(t) base band conjunction road signal for recovering from ideal signal;

● S _real-PreProc(t) base band conjunction road signal for recovering from measured signal.

B () is for conjunction road signal:

● S _reft () is desirable low-pass equivalent base band conjunction road signal;

● S _{ideal-PreProc}(t) base band conjunction road signal for recovering from ideal signal;

● S _real-PreProc(t) base band conjunction road signal for recovering from measured signal;

(8) utilize the base band navigation signal that step (4) draws, draw the relevant peaks curve of navigation signal, calculate S curve skew;

First the S curve of code Discr. is calculated:

$\mathrm{SCurve}(\mathrm{\ϵ},\mathrm{\δ})={\left|\mathrm{CCF}(\mathrm{\ϵ}-\frac{\mathrm{\δ}}{2})\right|}^2-{\left|\mathrm{CCF}(\mathrm{\ϵ}+\frac{\mathrm{\δ}}{2})\right|}^2$

Wherein, δ is coherence interval.SCurve (ε _bias(δ), δ)=0 time ε _bias(δ) be code phase when code ring is restrained.

The computing method of the SCB value of signal are:

SCB(δ)=ε _bias(δ)-ε _bias(0)

(9) data of each collection after arriving to pulse per second (PPS) rising edge all utilize above-mentioned steps (3) to calculate pseudo-code phase, obtain the pseudo-code phase of 24 hours, utilize the pseudo-code phase calculation delay stability of 24 hours;

Calculation delay stability is specially:

(9.1) utilize step (3) to obtain the pseudo-code phase of 24 hours, phase value number is 86400;

(9.2) by the pseudo-code phase of 24 hours in units of 100 o'clock, order divide into groups, obtain 864 groups;

(9.3) ask the mean value of interior 100 pseudo-codes of each group, obtain 864 mean values;

(9.4) maximal value of these 864 mean values is deducted minimum value, difference is as delay stability of time.

Claims (3)

1. a defining method for satellite navigation signals quality assessment parameter, is characterized in that: described satellite navigation signals quality assessment parameter comprises Gabor bandwidth, error vector magnitude EVM, range error, phase error, pseudo-code consistance, phase deviation, associated loss, S curve skew and delay stability of time;

Concrete steps are as follows:

(1) sample frequency f is set _s, utilize satellite navigation signals generated clock source, generate sampled clock signal and pps pulse per second signal, same source sampling is carried out to described satellite navigation signals, obtain the navigation signal after sampling;

(2) utilize the navigation signal after sampling, carry out the spectra calculation of navigation signal, and calculate Gabor bandwidth;

(3) time delay of each road pseudo-code relative to sampling start time and the carrier phase of each road pseudo-code in the navigation signal after calculating sampling, described pseudo-code is pseudo-code phase relative to the time delay of sampling start time;

The carrier phase of each road pseudo-code and pseudo-code phase in calculating navigation signal described in step (3), comprise the following steps:

(3.1) iteration step length of pseudo-code phase and carrier phase is set;

(3.2) carry out carrier phase calculating, concrete steps are as follows:

(3.2.1) according to carrier phase iteration step length, cosine carrier and the sinusoidal carrier with different initial phases are set, carry out mixing with measured signal;

(3.2.2) two paths of signals after mixing is by wave digital lowpass filter, and obtain I roadbed band signal and Q roadbed band signal, the bandwidth of low-pass filter is set as 1.5 times of navigation signal bandwidth;

(3.2.3) generate pseudo-random code, and the I roadbed band signal that obtains of step (3.2.2) and Q roadbed band signal carry out related operation respectively, obtain I road related function and Q road related function;

(3.2.4) I road related function step (3.2.3) obtained and Q road related function are added, and offset the cross-correlation part in two-way related function;

(3.2.5) using the sum functions of two-way related function as likelihood function, carry out maximal possibility estimation, draw the maximum likelihood estimator of carrier phase; Following formula is adopted to correct carrier phase estimated value

$\mathrm{\Δ\θ}=\arctan \left\{\frac{\mathrm{Cor}(Q,I)}{\mathrm{Cor}(I,I)}\right\}=\arctan \left\{\frac{\mathrm{Cor}(I,Q)}{\mathrm{Cor}(Q,Q)}\right\}$

Wherein, Δ θ is correcting value; Wherein I represents the conjunction road of each component of signal of branch road in the same way, and Q represents the conjunction road of each component of signal of quadrature branch, and Cor () represents related operation;

(3.3) the pseudo-code phase step calculating each road pseudo-code in navigation signal is as follows:

(A) utilize the cosine carrier phase place that step (3.2) obtains, peel off the carrier wave in navigation signal, obtain base band navigation signal;

(B) according to pseudo-code phase iteration step length, the base band navigation signal obtained is set and is correlated with, obtain related function in the pseudo-code and step (3.2.1) with different initial phases;

(C) related function step (3.2.2) obtained, as likelihood function, carries out maximal possibility estimation, draws the maximum likelihood estimator of pseudo-code phase;

(3.4) judge whether the precision of pseudo-code phase and carrier phase meets the accuracy requirement of navigation signal quality evaluation, if the method for meeting terminates, if do not meet, after the iteration step length of pseudo-code phase and carrier phase is reduced into original 0.1 times, proceed to step (3.2);

(4) carrier phase that step (3) draws is utilized, generate cosine and sinusoidal carrier, peel off the carrier wave in navigation signal, obtain I roadbed band navigation signal and Q roadbed band navigation signal, draw eye pattern and planisphere, calculate the error vector magnitude EVM of navigation signal, range error and phase error;

(5) utilize the pseudo-code phase that step (3) draws, calculate multichannel pseudo-code phase poor, determine pseudo-code consistance;

(6) utilize the carrier phase that step (3) draws, calculate multichannel carrier phase differential, calculate the phase deviation of component of signal;

(7) the base band navigation signal that the pseudo-code phase utilizing step (3) to draw and step (4) obtain, calculates associated loss;

(8) utilize the base band navigation signal that step (4) draws, draw the relevant peaks curve of navigation signal, calculate S curve skew;

(9) data of each collection after arriving to pulse per second (PPS) rising edge all utilize above-mentioned steps (3) to calculate pseudo-code phase, obtain the pseudo-code phase of 24 hours, utilize the pseudo-code phase calculation delay stability of 24 hours;

Calculate delay stability of time in described step (9) to be specially:

(9.1) utilize step (3) to obtain the pseudo-code phase of 24 hours, phase value number is 86400;

(9.2) by the pseudo-code phase of 24 hours in units of 100 o'clock, order divide into groups, obtain 864 groups;

(9.3) ask the mean value of interior 100 pseudo-codes of each group, obtain 864 mean values;

(9.4) maximal value of these 864 mean values is deducted minimum value, difference is as delay stability of time.

2. the defining method of a kind of satellite navigation signals quality assessment parameter according to claim 1, is characterized in that: carry out same source sampling described in step (1), comprises the following steps:

A () utilizes frequency synthesizer and the described clock source utilizing navigation signal to generate, the frequency described in generation step (1) is f _ssinusoidal signal;

B frequency is f by () _ssinusoidal signal incoming radio frequency signal collecting device, as the clock signal of RF signal collection equipment;

C clock source that () utilizes waveform generator and navigation signal to generate, generates pps pulse per second signal, pulse per second (PPS) to be the cycle be two level signals of 1 second;

(d) by pps pulse per second signal incoming radio frequency signal collecting device, as the trigger pip of collecting device;

E () starts collecting device;

F () arranges drainage pattern:

I (), when pulse per second (PPS) rising edge arrives, starts to gather;

(ii) acquisition time is the PN-code capture of the tested navigation signal of twice;

(iii) sample frequency is f _s;

(iv) after sampling terminates, data storage will be collected to obtain, wait for the arrival of pulse per second (PPS) rising edge next time, and start to gather next time;

V () whole collection duration is greater than 24 hours.

3. the defining method of a kind of satellite navigation signals quality assessment parameter according to claim 1, it is characterized in that: in described step (5), determine that pseudo-code consistance is specially: with a road any in multichannel pseudo-code for reference, this road pseudo-code phase and other each road pseudo-code phase are subtracted each other, and the maximal value of difference is as pseudo-code consistance.